A Siren's Lure
by EllaB twilight
Summary: Tumblr prompt: A siren-like creature with the ability to look like someone's true love. Sam and Dean will be in a motel working a case and Cas will have gone off for a beer run. Cas returns and Dean will be like, "Dude." But then he stops when he glances back at Sam, who looks petrified as fuck all of a sudden. When Sam finally gets his mouth working, he just says, "Jess?"


The clicking of keys on Sam's laptop across the motel room lulled Dean into a pleasant daze as he disassembled his Glock with practiced hands.

He always enjoyed this — the calm before the storm. They were getting very close to nailing down a hideout for a baddie who had been terrorizing the Cincinnati suburbs for months, but for now they had a few moments of peace. Dean always took it as an opportunity to maintain his weapons — nothing was worse than a gun jamming when shit gets real. Sam was checking a few last-minute details for their ambush and Cas had been sent on a beer run. It was a perfect time to catch their breaths and finish planning.

Preparation like this was crucial, especially given the cruel challenge of this latest hunt. Four people were dead, and witness testimony couldn't be trusted because every person claimed to have seen a different perpetrator. The one survivor had been committed to a mental facility after going after her husband with a gun — convinced he had been the one to try to kill her, although his alibi checked out.

Dean and Sam caught up with the thing in a dark, closed factory, wounding it when Sam's bronze hippy-dippy bracelet had connected with its skin. However, they only caught glimpses of a human-shaped form, which didn't narrow it down for them very much. Many creatures reacted to bronze. Sam had seen enough to be convinced that they were hunting a female, and Dean made a note of the khaki jacket it seemed to wear. After a week of the creature slipping past them, they had called in Cas for backup.

Dean assembled the final piece of the handgun with a satisfying click and loaded it carefully with the bronze-coated bullets he had obtained, reaching to do the same to Sam's weapon.

"Hey Dean, make sure to wash that bronze blade with purified water," Sam didn't even look up from his research. "The last time we used that was on the siren in Iowa, so it's been a while since it was cleaned."

"Think this thing could be a siren?"

Sam finally looked up. "No. Well…maybe." He shifted to face his brother. "It seems to have a lot of the same characteristics, like an aversion to bronze, but it's different too. Maybe we're dealing with something we haven't seen before."

Dean finished loading the final gun. "Dibs on naming it, then."

Sam rolled his eyes. "Please. The last thing we need is a new Jefferson Starship…or…"

"Say it Sammy."

"I'm not saying —"

"A were-pire!" Dean finished for him, grinning. The motel door opened with a click and Dean turned his grin on a returning Castiel. "Hey, Cas…remember the were—"

Sam's horrified gasp stopped Dean's joking cold in his throat. Darting his eyes at his brother, he was surprised to see Sam pale, his eyes wide and incredulous as he stared at Cas.

The oldest Winchester looked back at the angel, noticing his empty hands. "Dude, what the hell…where's the beer?"

Sam made a whining noise in his throat, and now Dean was convinced the two of them were fucking with him. "Okay, hahaha you two…seriously, Sam, what the fuck…"

Sam opened his mouth as if to talk, and closed it again, making him have the appearance of a dying fish. Cas chuckled lightly. The ratty hotel chair fell back as Sam clambered to his feet, eyes never leaving the angel.

Sam's strangled whisper punched its way out. "J…Jess?"

All thought went out of Dean's head at that moment. There was no way Sam would use Jessica's name in a prank against him. But something was wrong with his brother, and Dean took the few steps over to him.

"Hey…HEY! Look at me. Are you okay? What are you seeing?" Sam's wide gaze was fixed over Dean's shoulder at Castiel. Dean was beginning to worry that Sam was hallucinating when he saw the younger Winchester's eyes widen.

"You're not Jess!" he yelled as he shoved Dean to the side. A breeze whispered past Dean's ear, where Castiel's hand had just swiped, his nails elongated into claws.

"Cas!" Dean yelled as he rolled away from Sam, who had leapt forward to grapple with the angel. "What the hell?"

Castiel and Sam crashed backwards as they grappled, knocking into the pressed wood desk and sending a lamp flying. "How dare you," Sam seethed, catching Cas with a solid left hook. "You son of a bitch!"

"Stop it, you two!" Dean entered the fray, trying to pry the two of them apart and catching an elbow to the lip. "Fuck!" Sam was shoved back away from Cas, and he crumpled against one of the beds with a groan. Dean was preparing to tear Cas a new one — _because seriously, what the fuck_ — when the angel gripped his shoulders and threw him against the wall.

" _Something is possessing Cas_ ," Dean thought as he ducked to avoid a chair that came flying toward his head. It had to be the only explanation. They needed to find a way to immobilize the angel so they could perform an exorcism. The splinters from the fractured chair pierced his arms as Cas hauled him to his feet.

"Cas!" Dean's head rocketed back with the force of a punch. "Cas, please!"

"That's not Cas," Sam's voice was cold. Castiel dropped Dean and whirled toward the younger Winchester. Dean had no time to scream at his brother to stop before Sam pumped four bullets into Castiel. Cas fell with a thud, eyes open but unseeing.

"Oh shit, oh shit, Cas," Dean crawled toward the body, but froze in place when Sam dropped the gun, fell to the floor and began sobbing.

"Jessica…" he cried. "Oh, Jess, I'm so sorry."

Dean sat back, avoiding the puddle of blood that was pooling around Castiel's body, and scrubbed his hands through his hair. He needed to take a few deep breaths, or he'd start freaking out pretty soon. Castiel was dead, his brother was hysterical, and he had no idea what was going on. He might even shed a tear or two as well, if he weren't so numb with shock.

In the midst of Sam's tears, he began to rasp, "Dean…Dean, are you ok?"

Dean made his way to his brother, trying not to look at Castiel's open, glassy eyes. "Sammy, what the hell just happened?"

Sam's arm twitched toward the crumple of trench coat. "That's not Jess. It's not Cas, either. It's the siren." Dean finally allowed himself to look, but all he saw was a dead Cas. Bile rose in his throat.

"How can you be sure?"

Sam's eyes met his, and Dean could see the pain in them. "It was Jess, Dean. The siren looked like Jess. I knew it couldn't be real. And then when you said you saw Cas…I knew for sure."

"Knew what?"

"That this was the siren. It's taking on the appearance of someone we love the most."

Dean cleared his throat, his face suddenly hot for reasons unrelated to his swelling lip and blackening eye. "Well, that can't be right," he muttered, inching away from Sam. "I mean, you saw Jess…maybe I was seeing Jimmy Novak. Maybe it takes on the appearance of people we know who have died."

"Come on, Dean. It fits with everything else we've learned about it over the last week."

"Sammy, I—"

"I'm not blind," Sam interrupted. "I've known how you've felt for a long time now. Since you got back from Purgatory, at least."

Dean didn't even want to respond to that. Luckily, he didn't need to, because at that moment, the door opened and the real Castiel stood there, hands full of beer and pie. His brow furrowed in confusion as he took in the wrecked room, bloody body and disheveled brothers.

"Dean, Sam, what happened here?"

The brothers exchanged a glance. "Oh, you know…"

Castiel's voice hitched. "And Dean, why is there a clone of you lying dead on the floor?"


End file.
